Super high-density olive groves (>800 trees ha−1) are rapidly expanding in olive oil producer countries, which entails a strong modification of the olive growing system with important agronomic, ...economic, sociocultural, and environmental consequences. Among them, the latter is particularly unknown. The aim of this paper is to bring the attention on the environmental impacts of super high-density olive groves, by systematically reviewing the current evidence and identifying knowledge gaps yet to be filled. As a result, we can argue that new super high-density olive plantations reduce habitat heterogeneity and complexity, and the younger trees of these plantations impoverish habitat quality for farmland biodiversity. In addition, the high input use (e.g. phytosanitary treatments, fertilisers and water supply) may entail ecological impacts as well. Therefore, we conclude that i) new highly intensive olive groves should be limited to areas with lower ecological value; ii) consumers should have more information concerning how is produced the olive oil they buy, including the environmental impacts produced; iii) agricultural policies should be reformulated following the provider-gets principle; iv) input use (fertilisers, pesticides, water, etc.) should be gradually optimised to reduce the environmental impact; and finally, v) more research is necessary to foster decisions based on science.
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Hard coral coverage contributes to increasing the structural complexity of coral reefs, provides biological resources and drives biological and ecological interactions among reef organisms. Declines ...in the structural complexity and coral diversity of tropical reefs, due to the influence of anthropogenic activities, have been reported around the world in recent decades; however, coral reefs on the continental coast of Ecuador have been poorly studied. From September 2017 to April 2018, the method of permanent belt transects and quadrats was used to assess the status of coral (percentage of live, dead and fractured coral) to determine the contribution of derelict fishing gear to the process of coral fracture, which causes loss of structural complexity on two marginal coral-rocky reefs in the central coast of Manabi-Ecuador: Perpetuo Socorro and Ureles. Three geomorphological zones crest (5–7 m depth), slope (7–10 m depth) and bottom (10–13 m depth) were assessed. Results show that the crest zone in Ureles reef was highly affected by the entanglement of nets compared with Perpetuo Socorro, and identify derelict fishing gear as a key driver in the process of the fracturing and fragmentation of coral. Seasonal and site-associated factors also had a significant effect on the structural complexity of the reef studied. Destruction of coral in the crest zones drastically affects invertebrate and fish communities. We recommend a periodical assessment to measure the loss of structural complexity plus the implementation of a recovery program for the reefs studied that involves the education, active participation and collaboration of artisanal fishermen, governmental organizations and universities.
Agricultural intensification has greatly affected biodiversity in recent decades. One common and recent transformation that has taken place in Mediterranean countries is olive grove intensification, ...although its effects on biodiversity have rarely been studied.
In the present study, we investigated the effect of soil management practices, with versus without soil cover crops, on the arthropod abundance, richness, diversity and species composition in Andalusia olive groves, South Spain.
The results obtained show that these soil cover crops positively affect the diversity of arthropods, along with other variables such as the diversity of the plant community and Shannon index of the landscape. By contrast, the number of arthropods was higher in olive groves with bare ground as a result of the abundance of two families (Entomobryidae and Aeolothripidae), which comprised more than 50% of all the individuals collected.
Rank abundance diagrams and multivariate analyses showed differences between the two types of soil management systems with respect to the composition of families.
In conclusion, soil cover crops strongly improve the diversity of arthropods in olive orchards, which helps to maintain biodiversity in these intensive agroecosystems at the same time as improving other ecosystems services, such as soil fertility and the prevention of soil erosion.
Natural and human-induced stressors have threatened the sustainability of the fish communities of coral-rocky reefs worldwide in the last decades. The composition of the fish communities on the reefs ...of Ecuador and the factors affecting spatiotemporal changes are unknown. We studied the influence of the descriptors of structural complexity, the current status of coral and human-induced variables over fish communities. A video transect method was used to assess fish communities in three zones (slope, crest, and bottom) of two reefs during two seasons (rainy and dry). The structure of fish communities was highly influenced by the zones and season; rugosity and live coral affected the fish composition on the crest and slope zones. The fractured coral and derelict fishing gear on coral produced an adverse effect on fish composition over the crest. A multifactorial process causing loss of structural complexity and affecting fish composition was identified, however, periodical assessment is required for a greater understanding of this process.
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•Differences in the fish composition between the study sites, zones and seasons.•High presence and prevalence of derelict fishing gear.on the coral colonies on the crests.•Negative effects over fish composition in relation to derelict fishing gear and fractured coral.•Spatial and temporal changes in fish communities driven by a multifactorial degradation process.•Evidence of a possible major threat of habitat degradation to coral-dependent fish populations.
The intensification of agriculture has significant environmental consequences. This intensification entails the simplification and homogenisation of the landscape, which leads to strong negative ...impacts at ecosystem level, including declines in animal biodiversity. The purpose of this study was to assess the effect of different land uses on reptilian and amphibian biodiversity patterns at a regional scale by analysing a large database on the presence of amphibians and reptiles in Andalusia (southern Spain). GIS techniques and the Ecological-Niche Factor Analysis (ENFA) were applied in order to assess whether the habitat was suitable for each reptilian and amphibian species, when the land use variables were excluded. The incongruence between the potential and the observed species richness was then correlated with the main types of land use in Andalusia. Our results showed that irrigated and unirrigated olive groves were associated with a biodiversity deficit of amphibians and reptiles respectively, whereas natural forests and pastures, along with more heterogeneous crops areas, were more suitable. A clustering analysis showed that generalist species were related to olive groves whereas rare and specialist species were related to land uses related to natural vegetation. In summary, our results indicate that large areas covered by olives groves harbour less amphibian and reptilian diversity, thus suggesting that agro-environmental schemes should be carried to promote the species richness in these crops.
•The species richness of amphibians and reptiles is reduced in olive groves.•Irrigated olive crops have a strong negative effect on amphibians but not on reptiles.•Generalist species are associated with olive groves whereas rare species are associated with other land uses.
The intensification of agriculture in olive groves, especially the modification or elimination of spontaneous vegetation, alters the relationships in arthropod communities and reduces their ...interactions and ecosystem services. This study was carried out in nine olive groves in which there was either a planted cover crop, spontaneous cover crop or bare ground. The interactions of ground-dwelling, canopy and fl ying arthropods in trophic webs were calculated for each olive grove soil management regime at the family level taking into consideration their different functional traits: feeding guilds, specifi c agricultural traits and trophic level. Olive groves with spontaneous cover had trophic webs with a higher number of plausible links between arthropod families and a more balanced distribution of specimens among trophic levels compared to those with planted cover and bare ground. There was a similar number of arthropod families consisting of both pests and their natural enemies in the planted cover regime, while olive groves with bare ground had simpler trophic webs. The complexity of plausible trophic links was greater in olive groves with spontaneous plant cover despite the similar values for family richness in the three-olive grove soil management regimes. Qualitative values (such as functional traits) were more diverse in agroecosystems with spontaneous plant cover in which there were more sources of food.
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•Agricultural practices driven by the ‘intensification’ have caused erosion problems.•The use of cover crops attenuates the problems related to erosion.•High rabbit abundances may ...prevent the establishment of cover crop.•Unpalatable species are a good alternative to establish these cover crops.•arvensis can contribute to soil conservation and improvement in olive groves.
Sustainability is a key attribute for the future of the olive grove. Cover crops can be considered as an effective tool to achieve sustainability of olive orchards to reduce soil erosion, improve soil fertility and increase biodiversity. However, wild herbivores may forage on cover crops when natural food resources are scarce. In this study we assessed the impact of European rabbit grazing on the implantation of herbaceous cover crops of two native plant species, one palatable (Bromus rubens L.) and the other unpalatable (Anthemis arvensis L.) in two olive orchards with very scarce vegetation cover in Andalusia, Southern Spain. Eight rabbit exclusion plots, close to eight other unfenced plots, were planted where the aboveground biomass, height and the ground covered by each species were measured. The results showed that the biomass, height and the ground cover by B. rubens were higher in the rabbit exclusion areas (ground cover: 36.5±3.3%; height: 30.3±3.9cm, averaged over the entire measuring period; and biomass: 158±36g/m2, in April) than in unfenced areas (ground cover: 1.9±0.2%; height: 5.6±0.7cm; biomass: ≅0), while A. arvensis showed no difference in biomass, height or ground cover between the two treatments (ground cover: 11.3±6.3%; height: 12.2±7.9cm, averaged over the entire measuring period; and biomass: 49.5±10g/m2, in April). The results further showed that the damage by rabbits was caused from the early stages of development of B. rubens, which avoid its growth; notwithstanding the plant biomass consumption was minimal, the damage caused was critical. These findings suggest that unpalatable species such as A. arvensis could be a suitable tool for establishing herbaceous cover crops in olive groves at high rabbit densities, where other palatable species (e.g., B. rubens) are strongly consumed, thus contributing to soil conservation and improvement in olive groves with soils already degraded by erosion.
Abstract
The lack of refuge has been suggested as one of the main factors affecting reptiles in intensive crops, but this theory has not been explored to any great extent. The aim of this work is to ...compare the reptile abundance and species richness between traditional and intensive vineyards and olive groves, and to test the acceptance of artificial shelter due to its scarcity in the new intensive woody crop. A total of 288 transects were carried out (144 in olive groves and 144 in vineyards) in six different types of plots: traditional olive groves, traditional vineyards, intensive olive groves with and without artificial refuge, and trellis vineyards with and without artificial refuge. The results showed a greater species richness and abundance of reptiles in the traditional plots than in the intensive plots (independently of the experimental refuges added). An important number of animals were observed using the artificial refuges in olive groves. Furthermore, most of the individuals were located on or escaped to old trees in traditional systems, including an important proportion of reptiles hidden in olive trunk cavities, whereas more individuals were observed on the ground in intensive systems. Our finding suggests the importance for reptile communities of the traditional agricultural systems due to the high availability of the refuge provided by old olive tree trunks and free-standing gobelet vineyards. Our results show that providing refuge may mitigate the negative effects of woody crops intensification on reptile communities.
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